Known in the art is arterial embolization by coarse dispersions of autologous clots, subcutaneous fat, muscle etc. (cf., for example, M. Kalish, L. Greenbaum, S. Silber, H. Goldstein: Traumatic Renal Hemorrhage Treatment by Arterial Embolization. The Journal of Urology, 1974, Vol. 112, No.1, p.138).
Such emboli can, even if thrombin is injected, make only temporary occlusions lasting from several hours to several days, since they are subjected to lysis, the vessel is prematurely recanalized and hemorrhage recurs. Moreover, such compositions can contain radiopaque and physiologically active substances only in the fluid used for dispersion of embolizing particles. The embolizing material cannot be strictly controlled and the prolonged action of physiologically active substances cannot be controlled at the site of emboli.
Also known in the art are compositions for arterial embolization, containing exogeneous materials, such as particles of natural or synthetic polymers, glass, metals in combination with water or physiological solutions (cf., S. Soimakallio, J. Lahtinen, S. Tanska: Arterial Embolisation in the Treatment of Malignant Tumours, Annales Chirurgiae et Gynaecologiae, 1981, Vo. 70, No. 3, p.112). These compositions contain irregularly shaped and sized particles and cannot ensure reliable embolization of vessels.
There are known compositions for embolization of blood vessels, containing water or a physiological solution and polymer particles of a specific size, either close to, or less than, the diameter of the catheter, which comprise a nonpolarpolymer (ethylcellulose, for example) as the basic particle material and a physiologically active preparation, mitomycin C, for example, which is released from the particles at a slow rate due to the low polarity of the polymer (cf., T. Kato, R. Nemoto et al, Cancer, 1981, V.48, No.3, pp.674-680).
However, it is not easy at all to introduce particles of the above composition into a blood vessel through a catheter because of friction and deceleration of the particles which agglomerate in the catheter and finally block it since its diameter exceed the particle diameter by a factor of two or three at the most. In consequence, such compositions can only be infused into a vessel in limited amounts, carrying a limited number of particles until the catheter is clogged. This small number of particles (emboli) can be only introduced with a large amount of the physiological solution. Thus, when the size of the emboli is 225 micrometers they can be infused as a dispersion in a dose of 10-75 mg at the most in 20 milliliters at the least of the physiological solution. This produces an extra load of the ballast solution on the blood vessel and, in addition, an embolus can stray into lateral vessels.